Controlled pressure endoscopic and percutaneous surgery

ABSTRACT

The present disclosure relates to systems and methods for controlling pressure during percutaneous and endoscopic surgeries, including percutaneous renal procedures, endoscopic uterine procedures, transurethral endoscopic procedures for the bladder or prostate, or any percutaneous or endoscopic procedure. The system can include a sheath and/or endoscope each having an inflow port providing access to an inflow channel extending from the inflow port to a distal portion of the sheath, and an outflow port providing access to an outflow channel extending from the outflow port to the distal portion of the sheath. The sheath can also include a pressure sensor configured to generate a pressure measurement, and an electronic processor configured to control fluid through at least one of the inflow port and the outflow port based on the pressure measurement.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

The present application is a national phase of PCT Application No.PCT/US2014/063102, filed Oct. 30, 2014, which claims priority benefitunder 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/897,483,filed Oct. 30, 2013, which is hereby incorporated by reference in itsentirety herein. Any and all applications for which a foreign ordomestic priority claim is identified in the Application Data Sheet asfiled with the present application are hereby incorporated by referenceunder 37 CFR 1.57.

BACKGROUND

1. Field

The present disclosure relates to methods and devices for a closedpercutaneous surgery.

2. Description of the Related Art

During percutaneous kidney stone surgery, a small puncture is made inthe back or side of a patient to allow access into the kidney forremoval of kidney stones, removal of tumors, or treatment of anatomicdefects or strictures. In conventional (open system) percutaneousendoscopic procedures, a 30 F inner diameter sheath is placed into thekidney and used to facilitate introduction of either a rigid or flexibleendoscope into the kidney. The endoscope is used to break up the stonesor treat the tumor or anatomic abnormality. The rigid percutaneousendoscopes come in different sizes but are often 24 or 26 F in size,while the smaller flexible endoscopes are often 16 or 18 F in size.

SUMMARY

Certain aspects of the disclosure are directed toward a system forcontrolling pressure during endoscopic and percutaneous surgeries. Thesystem can include an endoscope having a proximal portion and a distalportion. The endoscope can include an inflow port providing access to aninflow channel extending from the inflow port to the distal portion ofthe endoscope and/or an outflow port providing access to an outflowchannel extending from the outflow port to the distal portion of theendoscope. The endoscope can also include a pressure sensor (e.g., at ornear a distal portion of the endoscope). The pressure sensor cangenerate a pressure measurement. Further, the endoscope can include anelectronic processor configured to control fluid through at least one ofthe inflow port and the outflow port based on the pressure measurement.

In the above-mentioned aspect, the endoscope can include an inputcontrol configured to receive a desired pressure value. In certainaspects, the processor can be configured to increase flow of an irrigantthrough the inflow port when the pressure measurement is less than thedesired pressure value. In certain aspects, the processor can beconfigured to increase flow of a fluid out of the outflow port when thepressure measurement is greater than the desired pressure value.

Certain aspects of the disclosure are directed toward a system forcontrolling pressure during endoscopic and percutaneous surgeries. Thesystem can include a sheath having a proximal portion and a distalportion. The sheath can include an inflow port providing access to aninflow channel extending from the inflow port to the distal portion ofthe sheath and/or an outflow port providing access to an outflow channelextending from the outflow port to the distal portion of the sheath. Thesheath can also include a pressure sensor (e.g., at or near a distalportion of the sheath). The pressure sensor can generate a pressuremeasurement. Further, the sheath can include an electronic processorconfigured to control fluid through at least one of the inflow port andthe outflow port based on the pressure measurement.

In the above-mentioned aspect, the sheath can include an input controlconfigured to receive a desired pressure value. In certain aspects, theprocessor can be configured to increase flow of an irrigant through theinflow port when the pressure measurement is less than the desiredpressure value. In certain aspects, the processor can be configured toincrease flow of a fluid out of the outflow port when the pressuremeasurement is greater than the desired pressure value.

In the above-mentioned sheath aspects, the system can include a capconfigured to close a proximal end of the sheath. In certain aspects,the cap can be configured to receive an endoscope.

Certain aspects of this disclosure are directed toward a system forcontrolling pressure during endoscopic and percutaneous surgeries. Thesystem can include a sheath having a proximal portion and a distalportion. The sheath can include an inflow port providing access to aninflow channel extending from the inflow port to the distal portion ofthe sheath and/or an outflow port providing access to an outflow channelextending from the outflow port to the distal portion of the sheath. Thesheath can also include a pressure sensor (e.g., at or near a distalportion of the sheath). The pressure sensor can generate a firstpressure measurement. Further, the endoscope can include an electronicprocessor configured to control fluid through at least one of the inflowport and the outflow port based on the first pressure measurement. Thesystem can also include an endoscope configured to be introduced throughthe sheath. The endoscope can include an inflow port providing access toan inflow channel extending from the inflow port to the distal portionof the endoscope and/or an outflow port providing access to an outflowchannel extending from the outflow port to the distal portion of theendoscope. The endoscope can also include a pressure sensor (e.g., at ornear a distal portion of the endoscope). The pressure sensor cangenerate a second pressure measurement. Further, the endoscope caninclude an electronic processor configured to control fluid through atleast one of the inflow port and the outflow port based on the secondpressure measurement.

In the above-mentioned system aspect, the system can further include acap configured to close a proximal end of the sheath. The cap can beconfigured to receive the endoscope.

Certain aspects of this disclosure are directed toward a method ofcontrolling pressure in a renal collecting system. The method caninclude positioning a distal end of an endoscope in the collectingsystem; measuring the pressure in the collecting system; and controllingfluid flow through the endoscope based on the pressure measurement. Theendoscope can include an inflow port providing access to an inflowchannel extending from the inflow port to a distal portion of theendoscope and/or an outflow port providing access to an outflow channelextending from the outflow port to the distal portion of the endoscope.The endoscope can also include a pressure sensor. The pressure sensorcan be configured to generate a pressure measurement. The endoscope canalso include an electronic processor configured to control fluid throughat least one of the inflow port and the outflow port based on thepressure measurement.

The above-mentioned method can also include inputting a desired pressurevalue into an input control of the endoscope. In certain aspects, theprocessor can be configured to increase flow of an irrigant through theinflow port when the pressure measurement is less than the desiredpressure value. In certain aspects, the processor can be configured toincrease flow of a fluid out of the outflow port when the pressuremeasurement is greater than the desired pressure value.

Certain aspects of this disclosure are directed toward a method ofcontrolling pressure in a renal collecting system. The method caninclude positioning a distal end of a sheath in the collecting system;measuring the pressure in the collecting system; and controlling fluidflow through the sheath based on the pressure measurement. The sheathcan include an inflow port providing access to an inflow channelextending from the inflow port to a distal portion of the sheath and/oran outflow port providing access to an outflow port extending from theoutflow port to the distal portion of the sheath. The sheath can alsoinclude a pressure sensor. The pressure sensor can be configured togenerate a pressure measurement. The sheath can also include anelectronic processor configured to control fluid through at least one ofthe inflow port and the outflow port based on the pressure measurement.

The above-mentioned method can also include inputting a desired pressurevalue into an input control of the sheath. In certain aspects, theprocessor can be configured to increase flow of an irrigant through theinflow port when the pressure measurement is less than the desiredpressure value. In certain aspects, the processor can be configured toincrease flow of a fluid out of the outflow port when the pressuremeasurement is greater than the desired pressure value.

In certain aspects, the efflux can be monitored by a sensor on theefflux monitor. In routine percutaneous nephrostolithotomy, as thesurgeon is working, the influx drains from large two to four literbottles of saline. This saline flows into the kidney at a rapid rate andthe saline then flows out of the kidney at a rapid rate between thespace between the nephroscope and the inner diameter of the sheath. Theopen system facilitates the rapid flow of irrigation. A rapid flow ofirrigation may be beneficial when there is a lot of bleeding or if thestone pieces are fragmenting rapidly might obscure the surgeons view.However, in some circumstances, there is minimal bleeding and the hardstone is fragmenting slowly such that high flow rates are not required.With this system for closed percutaneous surgery, the system could beoperated in a fluid conservation mode. In this mode, a sensor in theefflux channel or at the tip of the scope can measure light transmissionacross the efflux in such a manner that if the light transmission hasbeen degraded by blood or particulates the sheath could increase theinflow and outflow automatically maintaining pressure and optimizingvisualization. If the efflux had no particulates and no blood, thetransmission of light is not impeded and the device could slow down theflow of the irrigation fluid to conserve the fluid efflux.

During the treatment of a large staghorn calculus, it is not unusual toconsume more than 400 liters of saline and during large cases the wastedisposal of empty bottles, hanging of fluids, procuring new fluidbottles and emptying old fluid bottles can consume the time of one staffmember. Furthermore, if this staff member does not notice when theirrigation is getting low the procedure may be temporarily suspended dueto lack of irrigation until new bottles are obtained. In rarecircumstances, the hospital may even run out of irrigation resulting inpremature termination of the procedure. Hence the ability to operate onconserve mode when the irrigation is clear and doesn't need high flowrates could save money due to use of less irrigation bottles, requireless staff in the operating room, require less effort to clean up thefloor and significantly decrease the waste disposal and make theoperating room more green.

In another embodiment the nephroscope itself could have a sensor thatwould measure the blood and particulates and give feedback to the devicewhich would automatically increase or decrease the flow rate.

In conventional percutaneous nephrostolithotomy the saline that goes into the patient subsequent is mixed with the patient's blood inside therenal pelvis and then subsequently drains outside the sheath and ontothe flank of the patient. There are drapes that are designed to maintaina seal with the patient, but invariably, fluid escapes underneath thedrape and dribbles down the side of the patient and subsequently ends upon the floor where it may short out the electrical switches that thesurgeon is using to operate the foot pedals designed to operateequipment. This bloody saline effluent may contain hepatitis, AIDS, orother infectious diseases and subsequently the surgeon is exposed tothese infectious organisms due to their feet and legs being constantlywet. The ability to turn open into closed percutaneous surgery maysignificantly reduce the infectious risk for the surgeon as the fluidflow would be maintained in a closed system and leakage would be muchless. In addition, the floor would not be wet and require separatesuction devices or blankets placed by the nurse to keep the staff fromsustaining an injury due to slipping on the floor.

Any feature, structure, or step disclosed herein can be replaced with orcombined with any other feature, structure, or step disclosed herein, oromitted. Further, for purposes of summarizing the disclosure, certainaspects, advantages, and features of the inventions have been describedherein. It is to be understood that not necessarily any or all suchadvantages are achieved in accordance with any particular embodiment ofthe inventions disclosed herein. No aspects of this disclosure areessential or indispensable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a percutaneous access sheath inserted into a patient.

FIG. 2 illustrates a system with an embodiment of a cap secured to thepercutaneous access sheath.

FIG. 3 illustrates a system with an endoscope extending through anotherembodiment of a cap secured to the percutaneous access sheath.

FIG. 4 illustrates a perspective view of the cap shown in FIG. 3.

FIG. 5 illustrates a perspective view of yet another embodiment of thecap having inflow or outflow ports.

FIG. 6 is a schematic representation of a system including the cap shownin FIG. 5.

FIG. 7 illustrates a top view of yet another embodiment of a cap havinga closure mechanism.

FIG. 8 illustrates a perspective view the cap shown in FIG. 7 with theclosure mechanism in a closed configuration.

FIG. 9 illustrates a perspective view of the cap shown in FIG. 8 withthe closure mechanism in an open configuration.

FIG. 10 illustrates a perspective view another embodiment of a capsecured to the percutaneous access sheath.

FIG. 11 illustrates a perspective view of yet another embodiment of thecap secured to the percutaneous access sheath.

FIG. 12 illustrates a block diagram of an embodiment of a process thatcan be carried out by a system including the cap, the sheath, and/or theendoscope.

FIG. 13 illustrates a block diagram of another embodiment of a processthat can be carried out by a system including the cap, the sheath,and/or the endoscope.

FIG. 14 is a schematic representation of a pressure-controlling sheath

FIG. 15 is a schematic representation of a pressure-controllingendoscope.

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should in no way be interpreted as limitingthe scope of the embodiments. Furthermore, various features of differentdisclosed embodiments can be combined to form additional embodiments,which are part of this disclosure.

DETAILED DESCRIPTION

Open surgery can be problematic because there is no pressure to limitbleeding vessels and the system is open to bacterial infection, drying,and other physiologic changes. Similarly, endoscopic surgery, inparticular percutaneous intrarenal surgery, today is performed in anopen fashion where the pressure is not controlled and alterations in theintrarenal pressure may have serious consequences. Pressures that aretoo low may result in excessive venous bleeding, impaired visibility,and collapse of the renal collecting system. Pressures that are too highmay rupture the renal collecting system and increase opportunities forbacteria and fluids to move into the intravascular space or perinephricspace, potentially resulting in fluid shifts and even urosepsis.

There can be tremendous variation in intrarenal pressures duringpercutaneous renal surgery depending on the type of endoscope, number oftracts, and position of the tracts. A smaller, flexible endoscope allowsa surgeon to navigate the anatomy to access portions of the kidney thatare not ordinarily accessible with a straight, rigid endoscope, therebydecreasing the number of access sites. However, the irrigant flowthrough the smaller, flexible endoscope is less than the irrigant flowthrough the larger, rigid endoscope. Further, the amount of spacebetween the flexible endoscope and the sheath is significantly greaterthan the amount of space between the rigid endoscope and the sheath. Ifa 26 F rigid endoscope is introduced through a 30 F inner diametersheath, there remains only a small amount of space for irrigationoutflow. By comparison, if a 16 F flexible endoscope is introducedthrough a 30 F sheath, there remains a very large amount of space foroutflow. In addition, when switching from a rigid endoscope to aflexible endoscope, the irrigant draining from the tract becomesbloodier, in many instances making it difficult to visualize the anatomywhen using the flexible endoscope.

The pressure in the renal collecting system is significantly decreasedwhen irrigating with the smaller, flexible endoscope compared to thelarger, rigid endoscope. A lower pressure inside the renal collectingsystem decreases the ability to visualize the anatomic structures insidethe renal collecting system. This decreased visualization stems from twonegative effects. First, increased blood content in the renal collectingsystem causes dense pigments like hemoglobin to be in the salineirrigation. The pigments absorb the light energy and decreasevisualization. Second, with a lower pressure, the renal collectingsystem usually appears collapsed, making it difficult to visualize theinternal anatomy of the kidney and to identify specific calices andstones in those calices. The collapsed folds of the renal collectingsystem also make it difficult to maintain the orientation of theendoscope while inside the kidney and may make it difficult to identifythe opening into a specific calix bearing pathology (stone or tumor).

An alternative strategy to using the flexible endoscope is to usemultiple access tracts in an attempt to remove stones located at sitesthat cannot be reached using the rigid endoscope from the primary accesssite (see FIG. 1). FIG. 1 illustrates a patient with a standard sheath 2inserted percutaneously. The use of a second access site can improveirrigation flow by reducing the resistance to the outflow of salineirrigation. However, despite the better irrigant flow rate,visualization can still be impaired, as the pressure in the collectingsystem has been shown to drop down to close to the baseline pressurewhen a second access sheath is in place. In addition, patients receivingtwo nephrostomy tracts experience a larger amount of bleeding and have asignificantly greater risk of requiring a blood transfusion. When usingtwo tracts, the pressure can still be too low to provide tamponade ofvenous bleeding and to maintain expansion of the collecting systemmaking it more difficult to see the collecting system and harder tolocate the pathology.

Percutaneous tracts placed vertically can increase the pressure in therenal collecting system. The vertical tract can create a column of fluidthat fills the nephrostomy tube and places additional pressure on thecollecting system. Any pressure in the collecting system that is belowthe pressures in the renal capillaries, veins, or veinules can increasevenous bleeding from the kidney, which can increase the patient's bloodloss. In contrast, pressures inside the renal collecting system that arehigher than the pressures in the renal capillaries, veins or veinuleswill decrease the amount of bleeding that the patient experiences. Theincreased blood loss increases the likelihood of needing a transfusionand increases surgical risks associated with increased fluid shifts. Inaddition, if the pressure is too high, the collecting system mayrupture. Further, there is an increased risk of pyelovenous backflow andpyelolymphatic backflow, which can introduce bacteria into thebloodstream and increase the risk of sepsis. In the face of collectingsystem injury, if pressures are too high, there can also be an increasein absorption of fluids with the subsequent risk of fluid overload inpatients.

Additional factors including, but not limited to, the height of thefluid irrigation source, the fluid level inside the irrigationcontainers, the angle of the nephrostomy tube, and the depth of skin,fat, and subcutaneous tissues, can all affect the pressure inside therenal collecting system.

Given the drawbacks listed above, there is a need to control fluidinflow and outflow during percutaneous procedures. The advantages wouldbe decreased blood loss, better exposure to the intrarenal anatomy,shorter operative time and improved surgical outcomes.

Cap System

As described above, the use of a second access site can improveirrigation flow by reducing the resistance to the outflow of salineirrigation. However, patients receiving two nephrostomy tractsexperience a larger amount of bleeding and have a significantly greaterrisk of requiring a blood transfusion. In these scenarios, it can bedesirable to control irrigant flow and pressure by closing off one of amultiple number of percutaneous access sheaths. The cap 4 can limitoutflow of irrigation until a prescribed pressure is reached (see FIG.2).

A common instance in which the cap 4 would be utilized is during apercutaneous nephrostolithotomy with a single tract in place. In thisinstance, the surgeon will be working at a mean renal pelvic pressure of20-35 mm Hg using the high flow rigid nephroscope. The system will beexpanded and the different calices would be easy to identify. Once thesurgeon has removed all of the stone that can be reached using thestraight rigid nephroscope, the surgeon would next need to move to a 16French flexible nephroscope. In open percutaneous surgery, the pressureinside the renal pelvis immediately drops from 20-35 down to 5-10 mm ofHg. The renal pelvis collapses and the surgeon has a hard timeidentifying the takeoffs to calices and is more likely to cause injuryto the urothelium while employing holmium laser lithotripsy. Using thecap 4, the outflow can be reduced when the surgeon is operating with asmaller scope and the pressure can be maintained at 20-30 mm Hg. Thesurgeon will still able to visualize the takeoffs to the calices, andbecause the system remains distended, there is less blood loss and lessof a chance for injury to the urothelium.

Another instance in which the occlusion cap 4 might be utilized is ifthe surgeon has obtained access in one portion of the kidney and hascompleted the removal of the stone in that portion of the kidney and nowneeds to move to another portion of the kidney to treat stone. In thenew location, the surgeon could apply a new second access sheath inanother area and begin working in this second area with the rigidnephroscope. However, since the new access site communicates with theoriginal access site the fluid would flow in through the rigidnephroscope in the new access site, but would flow out of both the firstand second access sites. Since the outflow is so high, the fluidpressure in the collecting system would be very low, the surgeon wouldhave increased bleeding, and decreased turgidity of the collectingsystem of the kidney meaning it would be more difficult to work withoutgrinding on the transitional lining.

The cap 4 could be placed on the second tract to occlude flow so thatthe pressure can be maintained while working through the second tract.As another example, if there is so much bleeding that the surgeon cannotsee even when using only one access sheath with a rigid scope, thesurgeon can use the cap 4 to maintain a higher pressure when using therigid scope with a conventional access sheath. This cap 4 could be usedvery simply with routine, currently available percutaneous accesssheaths to maintain the pressure in the collecting system. This cap 4could also be a component of the closed percutaneous surgery systemwhere the pressure and flow were specifically controlled using thesheath model or the specially designed nephroscope described below. Theinflow and outflow of conventional percutaneous nephroscopes could beused to maintain the pressure at the desired level with the cap 4 toturn the system from an open system to a closed system.

To reduce the amount of irrigation fluid used during the procedure, theentire system can be completely closed by filtering the irrigation fluidthrough a high level filter designed to filter out all bacteria,crystals, cells, and particulates and recirculating the filtered fluidback into the patient such that the irrigation bottle would never needto be changed during the entire case, freeing up the circulating nursefor other activities in the operating room.

As shown in FIG. 2, a proximal end of at least one of the percutaneousaccess sheaths 2 can be closed off using the cap 4 having main bodyportion including a closed end 6 and a wall portion 12. The cap 4 can besized such that an inner surface of the cap 4 surrounds an outer surfaceof the sheath 2. For example, if the sheath 2 has an outer diameter ofat least 33-34 F with an inner diameter of 30 F, the cap 4 can be atleast about 33-34 F, such as between about 30 F and about 35 F. The wallportion 12 can be between about 2 mm and about 20 mm long, for example,about 8 mm long or about 10 mm long. The cap 4 can be generallyfrustoconical, cylindrical, or any other shape suitable to surround thesheath 2.

The cap 4 can be secured to the sheath 2 using any connection mechanism,including, but not limited to, a screw fit, a snap fit, or a frictionfit. Further, the cap 4 can be constructed from a variety of materials,including, but not limited to, rubber, plastic, silicone, polyurethane,or PTFE, so the cap 4 can be adaptable to different sized sheaths and/orform a friction fit with the sheath 2.

As shown in FIG. 3, the closed end 6 of the cap 4 can include an opening8 sized to permit insertion of an endoscope 7. The opening 8 can besized to accommodate different sized endoscopes or different caps 4 canbe used for different sized endoscopes. The opening 8 can be between atleast about 1 F and/or less than or equal to about 28 F depending on thesize of the endoscope. If the opening 8 is sized to receive a large,rigid endoscope, the opening 8 can include a diameter that is at leastabout 20 F, for example, between about 20 F and about 24 F or betweenabout 24 F and about 28 F. If the opening 8 is sized to permit insertionof a smaller, flexible endoscope, such as an ureteroscope, a diameter ofthe opening 8 can be between about 4 F and about 12 F, such as about 4F, about 6 F, about 8 F, about 10 F, or about 12 F. For a cytoscope, thediameter of the opening 8 can be between about 8 F and about 20 F. Itmay be desirable for the opening 8 to be larger than the endoscope toprovide additional space for irrigant outflow and prevent excessfriction between the endoscope and the sheath.

As shown in FIG. 4, a sealing feature 10 can be positioned in theopening 8 to form a seal around the endoscope 7. The sealing feature 10can be a self-sealing valve, such as a slit valve or a flap valve. Forexample, the sealing feature 10 can include a number of flaps adapted toform a seal around the endoscope and prevent the escape of fluids. Thesealing feature 10 can be configured to release fluid above a setpressure. The set pressure can be between about 10 and 40 mm Hg, forexample, between about 18 and 25 mm Hg, such as about 20 mm Hg.

FIG. 5 illustrates another embodiment of the cap 4. The cap 4 caninclude any of the features described in connection with FIG. 4.Additionally, the cap 4 can include one or more ports 30, 32 positionedon main body portion of the cap 4.

As shown in FIG. 6, in a cap system 400, the inflow port 30 can provideaccess from an irrigation source 416 to a main lumen of the sheath 2 viainflow tubing 418. The inflow port 30 can be sized to allow sufficientirrigation fluid to flow from the irrigation source 418 through theinflow port 30, for example with the aid of a pump 414. The cap 4 caninclude an outflow port 32 that provides an outlet for fluid flowing outof the sheath 2. The outflow port 32 can be sized to allow fluid to flowout of the port to maintain visualization within the collecting systemin the body. Without a suction source, fluid can flow out of the outflowport 32 passively by gravity and pressure gradients. However, theoutflow port 32 can be connected to a valve and/or suction source 423via outflow tubing 422 to control outflow.

The cap 4 can include one or more pressure sensors 411 configured todetect the pressure within system. The pressure sensor 411 can bepositioned anywhere on the cap 4 (e.g., in the outflow port), in theinflow tubing 418, the outflow tubing 422, or elsewhere in the system(e.g., sheath or endoscope). The pressure measurements can betransmitted to a controller 412 in the cap 4 or connected to the cap 4.The pressure sensor can be hardwired to transmit information to thecontroller 412 or to transmit the information wirelessly.

The controller 412 can include a processor configured to calculate thepressure within the collecting system in the body based on the pressuresensor measurement and subsequently automatically control fluid inflowand outflow based on the pressure measurement. This can be helpful wherehigh flow is needed to clear bleeding, but pressure must still bemaintained to have a tamponade effect upon venous bleeding. This couldalso be configured and operated in the fluid conservation mode if thefluid were not being recycled so that the pressure could be maintainedwith minimal flow of irrigation fluid.

The cap 4 can be connected to an input control 413, so the surgeon canenter a desired renal collecting system pressure into the input control.Based on the pressure sensor measurements, the controller 412 cancontrol, by various algorithms, the inflow and outflow of fluid throughthe cap 4 and sheath 2, thereby controlling the pressure in thecollecting system. If the collecting system pressure exceeds the desiredpressure, fluid flow out of the outflow port 32 can be turned on orincreased until the pressure decreases to the desired level. Once thedesired pressure is achieved, the outflow of saline can be automaticallydecreased or stopped. If the pressure is too low, the pump 414 can beginpumping or increase pumping from a saline bottle via the inflow port 30until the desired pressure is achieved. Once the desired pressure isachieved, the inflow of saline can be automatically decreased orstopped.

The controller 412 can also take into consideration the amount ofvisibility in the renal collecting system. For example, one or moreoptical sensors 432 on the cap 4 or connected to the cap 4 can sensewhen the visibility is not clear and automatically adjust the inflowand/or outflow to maintain a clear irrigation field and a setpre-established pressure. A light 430 can be shined across the outflowtubing 422, inflow tubing 418, and/or sheath 2 and registered by anoptical sensor 432 positioned opposite the light emitter (see FIG. 6).Blood or debris that decreases the absorption of light by the sensor 432could signal the controller to increase the rate of suction by thesource of suction 423 and/or to increase the pump rate of the pump 414to increase inflow, thereby maintaining the same pressure and improvingvisibility.

In some embodiments, the cap 4 can include a closure mechanism 14 tosecure the cap 4 to the sheath 2 (see FIGS. 7-9). The closure mechanism14 can be configured to move between an open position and a closedposition in which the closure mechanism 14 applies pressure to the cap 4to secure the cap 4 to the sheath 2. The closure mechanism 14 can beadjustable for securing the cap 4 to different sized sheaths or a singlecap 4 can include different sized closure mechanisms for different scopesizes.

As shown in FIGS. 7-9, the closure mechanism 14 can include a cinchingfeature 16 circumferentially disposed around the wall portion 12 of thecap 4 and secured to the cap 4 at one or more positions around the cap4. The cinching feature 16 can include one or more wires or bandsconstructed from a polymer or metal (e.g., stainless steel, nitinol,rubber, or plastic). Each wire or band can include a single filament orinclude a multiple number of filaments braided together for addedstrength. Each wire or band can include a width between about 0.1 mm andabout 10 mm, such as between about 0.5 and about 4 mm.

The cinching feature 16 can include a tab 18 configured to move betweenan open position and a closed position. When the tab 18 is in the openposition, the cinching feature 16 has a perimeter that is larger than acircumference of the cap 4 (see FIGS. 7 and 9). When the tab 18 is inthe closed position, the perimeter of the cinching feature closes aroundthe cap 4 to hold the cap 4 in place (see FIG. 8). The closure mechanism14 can include a latch 20 secured over the cinching feature 16 to holdthe cinching feature 16 and/or tab 18 in a closed position.

FIG. 10 illustrates another exemplary embodiment of a cap 4′ having aclosure mechanism 14′ that secures a movable closed end portion 6′ tothe cap 4′. The closure mechanism 14′ can include a first band portion16 a and a second band portion 16 b. When the cap 4′ is secured to thesheath 2′, the first band portion 16 a can be circumferentially disposedaround the sheath 2′, while the second band portion 16 b can becircumferentially disposed around the closed end portion 6′. In certainaspects, the sheath 2′ can include a circumferential groove in which thefirst band portion 16 a is disposed. As shown in FIG. 11, the cap 4′ caninclude an opening 8′ with a sealing structure 10′ for receiving anendoscope.

The first and second band portions 16 a, 16 b can be constructed from apolymer or metal (e.g., stainless steel, nitinol, rubber, or plastic).Each band portion 16 a, 16 b can include a single filament or include amultiple number of filaments braided together for added strength.

The first and second band portions 16 a, 16 b can extends 360° aroundthe sheath or closed end portion 6′, or less than 360°, such as betweenabout 270° and about 300°, between about 300° and about 300°, or betweenabout 330° and about 360°.

A thickness of the second band portion 16 b can be less than or equal toa thickness of the first band portion 16 a.

A diameter of the second band portion 16 b can be less than or equal toa diameter of the first band portion 16 a. Each band portion 16 a, 16 bcan include a width between about 0.1 mm and about 10 mm, such asbetween about 0.5 and about 4 mm.

The first band portion 16 a can connect to the second band portion 16 bsuch that the second band portion 16 b can move relative to the firstband portion 16 a. The closure mechanism 14′ can include connector 24′,such as a hinge that permits the closed end portion 6′ to move betweenan opened position and a closed position in which the closed end portion6′ covers, plugs, or otherwise closes the end of the sheath 2′.

The closure mechanism 14′ can include a latch 20′ for securing the firstband 16 a relative to the second band 16 b. The latch 20′ can be securedto the first band 16 a and configured to engage a protruding feature 22′on the second band 16 b.

Although not shown, the cap could alternatively be a plug shaped to fitwithin a lumen of the sheath. In certain aspects, the plug can betapered to prevent the plug from slipping completely inside the sheath.In certain aspects, a diameter of an end portion of the plug can begreater than an internal diameter of the sheath to prevent the plug fromslipping completely inside the sheath.

FIG. 12 is a flow chart illustrating a process for controlling fluidflow through the cap 4. After the hardware and variables are initialized(block 202), the user can set the desired pressure (block 204).Thereafter, the pressure sensor 411 begins to detect the pressure (block206). These pressure readings can be taken constantly, periodically, oron command. The pressure readings could be taken many times a secondand/or continuously adjusted so that the pressure variations wereminimized. The pressure readings are transmitted to the controller 412.If the pressure sensor 411 is displaced from the collecting system inthe body, the controller 412 can calculate the collecting systempressure based on the pressure measurement. If the collecting systempressure exceeds the desired pressure (block 208), then the controller412 directs the source of suction 423 to increase fluid outflow (block210). Fluid is withdrawn until the collecting system pressure reachesthe desired pressure. If the collecting system pressure is too low(block 212), then the controller 412 directs the pump 414 to increasesaline inflow through the sheath (block 214). Saline is continuouslypumped into the sheath until the collecting system pressure reaches thedesired pressure.

FIG. 13 illustrates another process for controlling fluid flow throughthe sheath 2. The hardware and variables are initialized (block 252),which can include emitting light across fluid outflow from the sheath,e.g., across outflow tubing 422 extending from the outflow port 32. Anoptical sensor 432 opposite the light transmitter 430 can detect theamount of light transmitted through the fluid outflow by detecting theamount of light not absorbed by the fluid outflow (block 254). Theamount of detected light is indicative of the visibility in the surgicalfield. The readings can be taken constantly, periodically, or oncommand. The readings can be taken many times a second and/orcontinuously adjusted so the visibility in the surgical field ismaintained. The levels of detected light are transmitted to thecontroller 412. If the amount of detected light is indicative of reducedvisibility in the surgical field (block 256), the controller 412 candirect fluid flow through the inflow port and/or outflow port (block258). For example, if less than 98% of the light emitted is detected bythe optical sensor or less than about 95% of the light emitted isdetected by the optical sensor, then the controller 412 can increase therate of inflow or outflow to clear the field.

Although the flow charts in FIGS. 12 and 13 illustrate a feedbackmechanism for controlling both inflow and outflow, in some instances,the cap 4 only includes an inflow port 30 or an outflow port 32. In someinstances, even if the cap 4 includes both inflow and outflow ports 30.32, the controller 412 only controls fluid through one port. Forexample, the controller 412 may control fluid inflow through the inflowport 410 based on the pressure readings, but fluid outflow through theoutflow port may be continuous at all times, passively by gravity andpressure gradients. Alternatively, the outflow can be controlled by theoperator (e.g., slow, medium or high flow), while the inflow canautomatically adjust the inflow to a rate to maintain the pressure thatwas set, or vice versa. Outflow or inflow can be set to a scale such as1-10, or a rate of flow such as 1 cc/sec/5 cc/sec/10 cc/sec, etc.

Pressure-Controlling Sheath

FIG. 14 illustrates a schematic diagram of a pressure-controlling sheathsystem 100. Although not shown, the sheath 102 can include a cap 4, 4′with any of the features described above.

The sheath 102 can include one or more ports 110, 120 positioned near orat a proximal or external end of the sheath 102 or in the cap 4, 4′. Thesheath 102 can include an inflow port 110 that provides access to aninflow channel extending along at least a portion of a length of thesheath 102, and/or an outflow port 120 that provides access to anoutflow channel extending along at least a portion of the length of thesheath 102. The inflow and outflow channels could extend along anexterior of the sheath 102, within the walls of the sheath 102, throughseparate lumens in the sheath 102, or be the main lumen of the sheath102. If the inflow and/or outflow channels are separate from the mainlumen of the sheath 102, the inflow and/or outflow channels can flowinto the main lumen along any portion of the sheath 102 or flow out of adistal end of the sheath 102.

If the sheath 102 includes both an inflow port 110 and an outflow port120, the inflow and outflow ports 110, 120 can be about the same size ordifferent sizes. For example, the inflow port 110 can be larger than theoutflow port 120, such that the inflow rate is much greater than theoutflow rate. In this configuration, even if the suction is workingthrough the outflow port 120 and the ultrasonic lithotripsy portsimultaneously, the inflow would still be able to maintain a set renalpressure in the collecting system.

The inflow and outflow ports 110, 120 can be rigid and/or attached atright angles to the sheath. For example, the inflow and outflow ports110, 120 can be flanges positioned on or connected to the sheath 102such that flexible inflow tubing 118 or outflow tubing 122 can beattached to a respective port 110, 120. When the inflow tubing 118and/or outflow tubing 122 is connected to the respective port 110, 120,it may be desirable to include one or more tripods (not shown) tosupport the tubing 118, 122, so that the sheath 102 is not inadvertentlyremoved. Each tripod can be adjusted to the level of the sheath 102.Further, each tripod can include a groove to support the tubing 118,120.

The inflow port 110 can be sized to allow sufficient irrigation fluid toflow from a saline bottle 116 and through the port 110 with the aid of apump 114. The saline bottle 116 can hold at least about 4 liters, forexample, about 4 liters, about 5 liters, or about 6 liters. The inflowtubing 118 can extend from the saline bottle 116 to the port 110. Theinflow tubing 118 can connect to the saline bottle 116 and/or port 110using a screw fit, friction fit, luer, or other conventional mechanism.The connections can be reinforced with a ferrule, clip, or otherreinforcing feature. The inflow tubing 118 can be a high flow warmingtubing that allows for high irrigation flow of warm fluid to prevent thepatient's body temperature from dropping despite this rapid flow offluid. Further, the inflow tubing 118 can have a diameter sized todecrease resistance to fluid flow, for example, between about 6 mm and12 mm, such as between about 8 mm and about 10 mm.

The outflow port 120 can be sized to allow fluid to flow out of the portto maintain visualization within the collecting system in the body. Theoutflow tubing 122 can be connected to the outflow port 120 using ascrew fit, friction fit, luer, or other conventional mechanism. Theconnection can be reinforced with a ferrule, clip, or other reinforcingfeature. Without a suction source, fluid can flow out of the outflowport 120 passively by gravity and pressure gradients. The outflow tubing122 can be connected to a container to prevent the spillage of fluid inthe operating room. This fluid could also be recycled after beingfiltered and cycled back into the inflow channel.

As shown in FIG. 14, the outflow tubing 122 can be connected to a sourceof suction 123. For example, the outflow tubing 122 can be connected toa suction canister 123 having a high-flow semi-permeable membrane thatcan filter blood products, bacteria, and/or stone pieces and allow theirrigation fluid to be re-infused, thereby maintaining a closed systemand allowing recycling of irrigation fluid. This can be more costeffective and reduce down time associated with replacing the salinebottles. This mechanism could include a trap to allow stone crystals tobe collected to be sent for chemical analysis. In addition, the stonepieces could be cultured to allow the bacterial organisms inside thestones to be determined so that the patients could be placed upon theappropriate antibiotics. Alternatively or in addition to the source ofsuction, the outflow tubing 122 can include a valve that can controloutflow through the tubing 122.

The sheath 102 can include one or more pressure sensors 111 configuredto detect the pressure in the system (see FIG. 14). Although FIG. 14illustrates the pressure sensor 111 as being within the sheath 102, thepressure sensor 102 can be disposed anywhere along the system 100,including along the inflow tubing 118 or the outflow tubing 122 or inboth places. The pressure sensor 111 can be disposed at or near a distalend of the sheath 102, along an intermediate portion of the sheath 102,at or near a port 110, 120, at or near a proximal end of the tubing 118,122, or otherwise. For example, the pressure sensor 111 could be placedupon the tip of the nephroscope in a position where the fluid infusingand the suction would not have a direct effect on the pressuremeasurement. The pressure measurements can be transmitted to acontroller 112 in the sheath 102 or coupled to the sheath 102. Thepressure sensor 111 can be hardwired to transmit information along thesystem 100 to the controller 112 or to transmit the informationwirelessly.

The controller 112 can include a processor configured to calculate thepressure within the collecting system in the body based on the pressuresensor measurement and subsequently automatically control fluid inflowand outflow based on the pressure measurement. This can be helpful wherehigh flow is needed to clear bleeding, but pressure must still bemaintained to have a tamponade effect upon venous bleeding. This couldalso be configured and operated in the fluid conservation mode if thefluid were not being recycled so that the pressure could be maintainedwith minimal flow of irrigation fluid.

The sheath 102 can include an input control 113 disposed near a proximalend of the sheath 102. The surgeon can enter a desired renal collectingsystem pressure into the input control 113. In order to minimizebleeding while still providing collecting system distention but avoidingrupture or pyelovenous backflow, the desired pressure can be betweenabout 25 mm Hg and 40 mm Hg in patients with metabolic (noninfectiousstones), and somewhat lower, such as between about 15 mm Hg and about 30mm Hg in patients with infected stones. Based on the pressure sensormeasurements, the controller 112 can control, by various algorithms, theinflow and outflow of fluid through the sheath 102, thereby controllingthe pressure in the collecting system. If the collecting system pressureexceeds the desired pressure, fluid flow out of the outflow port 120 canbe turned on or increased until the pressure decreases to the desiredlevel. Once the desired pressure is achieved, the outflow of saline canbe automatically decreased or stopped. If the pressure is too low, thepump 114 can begin pumping or increase pumping from a saline bottle 116via the port 110 until the desired pressure is achieved. Once thedesired pressure is achieved, the inflow of saline can be automaticallydecreased or stopped.

The controller 112 can take into consideration the amount of visibilityin the renal collecting system. For example, one or more optical sensors132 on the sheath 102 or connected to the sheath 102 can sense when thevisibility is not clear and automatically adjust the inflow and/oroutflow to maintain a clear irrigation field and a set pre-establishedpressure. A light 130 could be shined across the outflow tubing 122,inflow tubing 118, and/or sheath 102 and registered by an optical sensor132 positioned opposite the light emitter (see FIG. 14). Blood or debristhat decreases the absorption of light by the sensor could signal thecontroller 112 to increase the rate of suction by the source of suction123 and to increase the pump rate of the pump 114 to increase inflow,thereby maintaining the same pressure and improving visibility.

The sheath 102 can employ a similar process as illustrated in FIGS. 12and/or 13. Although the flow charts in FIGS. 12 and 13 illustrate afeedback mechanism for controlling both inflow and outflow, in someinstances, the sheath 102 only includes an inflow port 110 or an outflowport 120. In some instances, even if the sheath 102 includes both inflowand outflow ports 110, 112, the controller 112 only controls fluidthrough one port. For example, the controller 112 may control fluidinflow through the inflow port 110 based on the pressure readings, butfluid outflow through the outflow port may be continuous at all times,passively by gravity and pressure gradients. Alternatively, the outflowcan be controlled by the operator (e.g., slow, medium or high flow),while the inflow can automatically adjust the inflow to a rate tomaintain the pressure that was set, or vice versa. Outflow or inflow canbe set to a scale such as 1-10, or a rate of flow such as 1 cc/sec/5cc/sec/10 cc/sec, etc.

Pressure Controlling Endoscope

FIG. 15 illustrates a schematic diagram of a pressure-controllingendoscope system 300. Although not shown, the sheath can include a cap4, 4′ with any of the features described above, through which theendoscope 306 can extend (see FIG. 3).

Depending on the size of the patient, the endoscope 306 can be at leastabout 15 cm long and/or less than or equal to about 30 cm long, forexample, between about 15 cm and about 20 cm, between about 20 cm andabout 25 cm, or between about 25 cm and about 30 cm.

The endoscope 306 can include a diameter that is between about 15 F andabout 30 F, for example, between about 16 F and 18 F, between about 18 Fand 20 F, between about 20 F and about 22 F, between about 22 F andabout 24 F, between about 24 F and about 26 F, between about 26 F andabout 28 F, or between about 28 F and about 30 F. As an example, theendoscope 306 can be about 20 cm long and have an outer diameter ofabout 24 F or 26 F.

The endoscope 306 can include one or more working lumens. Depending onthe size of the endoscope 306, the endoscope 306 can include a workinglumen that is at least about 9 F and/or less than or equal to about 22F.

The endoscope 306 can be constructed from stainless steel or any othersuitable medical grade material.

The endoscope 306 can include a conventional rod lens. Alternatively, afiber optic bundle can convey the image to the surgeon. The image can becaptured by a CMOS or “chip on a stick” technology and deliveredelectronically. The endoscope can also include any of the camerafeatures described in U.S. Publication No. 2014/0309677, filed Apr. 10,2014, which is hereby incorporated by reference in its entirety.

The endoscope 306 can include one or more ports 310, 320 near or at aproximal end of the endoscope 306. For example, the endoscope 306 caninclude an inflow port 310 and/or an outflow port 320. The inflow andoutflow ports 310, 320 can be about the same size or different sizes. Insome instances, the inflow port 310 can be larger than the outflow port320.

The inflow port 310 can be sized to allow sufficient irrigation fluid toflow from a saline bottle 316 and through the port 310 with the aid of apump 314. The saline bottle 316 can hold at least about 4 liters, forexample, about 4 liters, about 5 liters, or about 6 liters. Inflowtubing 318 can extend from the saline bottle 316 to the port 310. Theinflow tubing 318 can connect to the saline bottle 316 and/or port 310using a screw fit, friction fit, luer, or other conventional mechanism.The connections can be reinforced with a ferrule, clip, or otherreinforcing feature.

The inflow tubing 318 can have a diameter sized to decrease resistanceto fluid flow, for example, between about 6 mm and 12 mm, such asbetween about 8 mm and 10 mm. In some configurations, it may bedesirable to use a high flow warming tubing that facilitates highirrigation flow.

Although not shown, the inflow port 310 can provide access to an inflowchannel extending from the port 310 to a distal portion of the endoscope306. In some configurations, the inflow channel can be shaped as a ringsurrounding an outer periphery of the endoscope 306. A distal end of theinflow channel can be configured (e.g., tapered) to direct the irrigantinward to stabilize the kidney stone at the center of the working area.

In some configurations, the inflow channel can extend from the port tothe distal portion of the endoscope 306. At the distal portion of theendoscope 306, the inflow channel can include a number of exit openingspositioned to form a ring. The ring can surround an outer periphery ofan end face of the endoscope 306. Each opening can be angled such thatthe irrigation fluid converges at a focal point, for example, about 1 to2 cm from the end of the endoscope.

In some configurations, the irrigation inflow channel can be positionedoff center from the central axis of the endoscope 306. The inflowchannel can be positioned at a 6 o'clock position relative to the imagesensor to avoid obstructing the image. The inflow channel should besized to allow rapid infusion of fluid. Depending on the size of theendoscope, the inflow channel can have a lumen sized between about 6 Fand 20 F, for example, between about 6 F and about 8 F, between about 8F and about 10 F, between about 10 F and about 12 F, between about 12 Fand about 14 F, between about 14 F and about 16 F, between about 16 Fand about 18 F, or between about 18 F and about 20 F.

In some configurations, the inflow channel can be distinct from theendoscope 306 and can extend toward an end portion of the endoscope toprevent inadvertent cycling of the fluid from the infusion port to theoutflow port without entering the collecting system of the kidney. Theinflow channel can include a diameter large enough to maintain thepressure even when the ultrasonic or other probe is suctioning.

Although not shown, the outflow port 320 can provide access to anoutflow channel extending from the port to a distal portion of theendoscope 306. The outflow port 320 can be sized to allow fluid to flowout of the port 320 to maintain visualization within the collectingsystem. Outflow tubing 322 can be connected to the outflow port 320using a screw fit, friction fit, luer, or other conventional mechanism.The connection can be reinforced with a ferrule, clip, or otherreinforcing feature. Without a suction source, fluid can flow out of theoutflow port 320 passively by gravity and pressure gradients. Theoutflow tubing 322 can be connected to a container to prevent thespillage of fluid in the operating room.

As shown in FIG. 15, the outflow tubing 322 can be connected to a sourceof suction 323. For example, the outflow tubing 322 can be connected toa suction canister. If the surgeon is working without the ultrasoniclithotripter or other methods of suctioning out stone fragments, theseparate source of suction 323 can be used to suction at a rate to keepthe field clear.

The outflow channel can have a lumen sized between about 4 F and about16 F, for example, between about 10 F and about 13 F. In some instances,the outflow channel can be smaller than the inflow channel.

Outflow through the outflow channel can be turned on and off. If thereis suitable visualization, outflow can be turned off by closing a valveor turning off suction. When bleeding increases, the surgeon can turn onthe outflow by opening the valve or turning on suction. In someinstances, the surgeon can manually control the flow rate by increasingor decreasing the size of a valve opening or controlling the level ofsuction. In some configurations, instead of or in addition to an outflowchannel, an ultrasonic lithotripter can be introduced through theworking lumen and used to remove fluid.

Instead of a separate outflow channel, the suction source 323 can beattached to the general working port lumen and just suction out throughthe working lumen. In this configuration, the endoscope 306 may onlyinclude a single inflow port 310 or include two ports 310, 320 forinflow. For example, if the ultrasonic lithotripter is being usedthrough the scope, the ultrasonic lithotripter can be used for suctionand both ports 310, 320 can simultaneously be used for inflow tomaintain the pressure at the prescribed setting. Two different salinesources can be attached to the ports 310, 320.

As shown in FIG. 15, the endoscope 306 can include one or more pressuresensors 314 configured to detect the pressure within the renalcollecting system. The pressure sensor 314 can be disposed anywherealong the system 300. For example, the pressure sensor 314 can bedisposed at or near a distal end of the endoscope 306, along anintermediate portion of the endoscope 306, at or near a port 310, 320,near a proximal end of the tubing 318, 322, or otherwise. The pressuremeasurements can be transmitted to a controller 312 disposed at aproximal portion of the endoscope 306. The pressure sensor 314 can behardwired to transmit information to the controller 312 or wirelesslytransmit information to the controller 312.

The controller 312 can include a processor configured to calculate thepressure within the renal collecting system based on the pressure sensormeasurement and control fluid inflow and/or outflow based on thecollecting system pressure. This can be helpful where high flow isneeded to clear bleeding, but pressure must still be maintained to havea tamponade effect upon venous bleeding.

The controller 312 can take into consideration the amount of visibilityin the renal collecting system. For example, one or more optical sensors332 on the endoscope 306 or connected to the sheath can sense when thevisibility is not clear and automatically adjust the inflow and/oroutflow to maintain a clear irrigation field and a set pre-establishedpressure. A light 330 could be shined across the outflow tubing 322,inflow tubing 318, and/or endoscope 306 and registered by an opticalsensor 332 positioned opposite the light emitter (see FIG. 15). Blood ordebris that decreases the absorption of light by the sensor could signalthe controller 312 to increase the rate of suction by the source ofsuction 323 and to increase the pump rate of the pump 314 to increaseinflow, thereby maintaining the same pressure and improving visibility.

The endoscope 306 can include an input control 313 disposed near aproximal end of the endoscope 306. The surgeon can enter a desiredcollecting system pressure into the input control. In order to minimizebleeding while still providing collecting system distention and avoidingrupture or pyelovenous backflow, the optimal pressure can be betweenabout 25 mm Hg and about 40 mm Hg in patients with metabolic(noninfectious stones) and somewhat lower, such as between about 15 mmHg and about 30 mm Hg in patients with infected stones. Based on thepressure sensor measurements, the controller 312 can control, by variousalgorithms, the inflow and outflow of fluid through the endoscope,thereby controlling the pressure in the renal collecting system. If thecollecting system pressure exceeds the desired pressure, fluid flow outof the outflow port 320 can be turned on or increased until the pressuredecreases to the desired level. Once the desired pressure is achieved,the outflow of saline can be automatically decreased or stopped. If thepressure is too low, the pump 314 can begin pumping or increase pumpingfrom a saline bottle 316 via the port 310 until the desired pressure isachieved. Once the desired pressure is achieved, the inflow of salinecan be automatically decreased or stopped.

The endoscope can employ a similar process as illustrated in FIGS. 12and/or 13. In some instances, the endoscope 306 only includes an inflowport 310 or an outflow port 320. In some instances, even if theendoscope 306 includes both inflow and outflow ports 310, 320, thecontroller 312 only controls fluid through one port. For example, thecontroller 312 may control fluid inflow through the inflow port 310based on the pressure readings, but fluid outflow through the outflowport may be continuous at all times, passively by gravity and pressuregradients. Alternatively, the outflow can be controlled (e.g., slow,medium or high flow), while the inflow can automatically adjust theinflow to a rate to maintain the pressure that was set, or vice versa.Outflow or inflow can be set to a scale such as 1-10, or a rate ofoutflow such as 1 cc/sec/5 cc/sec/10 cc/sec, etc.

Pressure-Controlling System

Any combination of the cap system, pressure-controlled sheath, and/orpressure-controlled endoscope described above can be used together. Ifthe system includes one or more the pressure-controlled cap,pressure-controlled sheath, and pressure-controlled endoscope, thesystem can include one or more pressure sensors or optical sensorspositioned on the cap, endoscope, and/or the sheath. The cap, sheath,and/or endoscope can control pressure using pressure measurements fromdifferent pressure sensors or the same sensor or control visibilitybased on the amount of detected light from the one or more opticalsensors. Further, the system can include one or more inflow and/oroutflow ports disposed on the cap, the endoscope, and/or the sheath. Forexample, the cap, the endoscope, and the sheath can each include inflowand outflow ports. As another example, each of the cap, the endoscope,and/or sheath can include an inflow port or an outflow port. Using theseapparatuses together will maintain the optimal flow and clarity of thefluid during the procedure.

TERMINOLOGY

Although certain embodiments have been described herein with respect torenal procedures, the sheaths and endoscopes described herein can beused during other percutaneous or endoscopic surgeries, such asarthroscopy, percutaneous spine surgery, cystoscopy, ureteroscopy, andhysteroscopy.

As used herein, the relative terms “proximal” and “distal” shall bedefined from the perspective of the sheath or endoscope. Thus, proximalrefers to the direction of the portion of the sheath or endoscopeexternal to the patient and distal refers to the direction of theportion of the sheath or endoscope within the patient.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements, and/or steps areincluded or are to be performed in any particular embodiment. The terms“comprising,” “including,” “having,” and the like are synonymous and areused inclusively, in an open-ended fashion, and do not excludeadditional elements, features, acts, operations, and so forth. Also, theterm “or” is used in its inclusive sense (and not in its exclusivesense) so that when used, for example, to connect a list of elements,the term “or” means one, some, or all of the elements in the list.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately,” “about,” and “substantially” may refer to an amountthat is within less than 10% of the stated amount, as the context maydictate.

The ranges disclosed herein also encompass any and all overlap,sub-ranges, and combinations thereof. Language such as “up to,” “atleast,” “greater than,” “less than,” “between” and the like includes thenumber recited. Numbers preceded by a term such as “about” or“approximately” include the recited numbers. For example, “about 30 F”includes “30 F.”

Although certain embodiments and examples have been described herein, itwill be understood by those skilled in the art that many aspects of thepressure-controlling features shown and described in the presentdisclosure may be differently combined and/or modified to form stillfurther embodiments or acceptable examples. All such modifications andvariations are intended to be included herein within the scope of thisdisclosure. A wide variety of designs and approaches are possible. Nofeature, structure, or step disclosed herein is essential orindispensable.

Some embodiments have been described in connection with the accompanyingdrawings. However, it should be understood that the figures are notdrawn to scale. Distances, angles, etc. are merely illustrative and donot necessarily bear an exact relationship to actual dimensions andlayout of the devices illustrated. Components can be added, removed,and/or rearranged. Further, the disclosure herein of any particularfeature, aspect, method, property, characteristic, quality, attribute,element, or the like in connection with various embodiments can be usedin all other embodiments set forth herein. Additionally, it will berecognized that any methods described herein may be practiced using anydevice suitable for performing the recited steps.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures are described herein. It is to be understood that notnecessarily all such advantages may be achieved in accordance with anyparticular embodiment. Thus, for example, those skilled in the art willrecognize that the disclosure may be embodied or carried out in a mannerthat achieves one advantage or a group of advantages as taught hereinwithout necessarily achieving other advantages as may be taught orsuggested herein.

Moreover, while illustrative embodiments have been described herein, thescope of any and all embodiments having equivalent elements,modifications, omissions, combinations (e.g., of aspects across variousembodiments), adaptations and/or alterations as would be appreciated bythose in the art based on the present disclosure. The limitations in theclaims are to be interpreted broadly based on the language employed inthe claims and not limited to the examples described in the presentspecification or during the prosecution of the application, whichexamples are to be construed as non-exclusive. Further, the actions ofthe disclosed processes and methods may be modified in any manner,including by reordering actions and/or inserting additional actionsand/or deleting actions. It is intended, therefore, that thespecification and examples be considered as illustrative only, with atrue scope and spirit being indicated by the claims and their full scopeof equivalents.

Any methods disclosed herein need not be performed in the order recited.The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication. For example,actions such as “positioning a distal end of an endoscope in thecollecting system” include “instructing the positioning a distal end ofan endoscope in the collecting system.”

Depending on the embodiment, certain acts, events, or functions of anyof the processes or algorithms described herein can be performed in adifferent sequence, can be added, merged, or left out altogether (e.g.,not all described operations or events are necessary for the practice ofthe algorithm). Moreover, in certain embodiments, operations or eventscan be performed concurrently.

The various illustrative logical blocks, modules, routines, andalgorithm steps described in connection with the embodiments disclosedherein can be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. The described functionality can beimplemented in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the disclosure.

Moreover, the various illustrative logical blocks and modules describedin connection with the embodiments disclosed herein can be implementedor performed by a machine, such as a general purpose processor device, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general purpose processor device can be amicroprocessor, but in the alternative, the processor device can be acontroller, microcontroller, or state machine, combinations of the same,or the like. A processor device can include electrical circuitryconfigured to process computer-executable instructions. In anotherembodiment, a processor device includes an FPGA or other programmabledevice that performs logic operations without processingcomputer-executable instructions. A processor device can also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration. Although described herein primarily with respect todigital technology, a processor device may also include primarily analogcomponents. For example, some or all of the signal processing algorithmsdescribed herein may be implemented in analog circuitry or mixed analogand digital circuitry. A computing environment can include any type ofcomputer system, including, but not limited to, a computer system basedon a microprocessor, a mainframe computer, a digital signal processor, aportable computing device, a device controller, or a computationalengine within an appliance, to name a few.

The elements of a method, process, routine, or algorithm described inconnection with the embodiments disclosed herein can be embodieddirectly in hardware, in a software module executed by a processordevice, or in a combination of the two. A software module can reside inRAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory,registers, hard disk, a removable disk, a CD-ROM, or any other form of anon-transitory computer-readable storage medium. An exemplary storagemedium can be coupled to the processor device such that the processordevice can read information from, and write information to, the storagemedium. In the alternative, the storage medium can be integral to theprocessor device. The processor device and the storage medium can residein an ASIC. The ASIC can reside in a user terminal. In the alternative,the processor device and the storage medium can reside as discretecomponents in a user terminal.

Example Embodiments

The following example embodiments identify some possible permutations ofcombinations of features disclosed herein, although other permutationsof combinations of features are also possible.

1. A sheath cap assembly configured to enclosed a proximal end of asheath, the cap comprising:

-   -   a main body portion comprising:        -   a wall portion shaped to surround the proximal end of the            sheath;        -   a closed proximal end portion; and        -   an open distal end portion;    -   an inflow port on the main body portion, the inflow port        providing access from an irrigation source to a lumen of the        sheath when the sheath cap is secured to the sheath;    -   an outflow port on the main body portion, the outflow port        providing an outlet for fluid flowing out of the sheath when the        sheath cap is secured to the sheath;    -   a pressure sensor connected to the sheath cap, the pressure        sensor configured to generate a pressure measurement; and    -   a processing unit configured to direct fluid through at least        one of the inflow port and the outflow port based on the        pressure measurement.

2. The sheath cap assembly of Embodiment 1, wherein the closed proximalend portion comprises an opening through which an endoscope can beintroduced.

3. The sheath cap assembly of Embodiment 2, wherein the openingcomprises a sealing structure configured to form a seal around theendoscope when the endoscope is introduced through the opening.

4. The sheath cap assembly of any one of Embodiments 1 to 3, furthercomprising a closure mechanism configured to secure the sheath cap tothe sheath.

5. The sheath cap assembly of any one of Embodiments 1 to 4, wherein thepressure sensor is positioned in the outflow port.

6. The sheath cap assembly of any one of Embodiments 1 to 5, furthercomprising outflow tubing connected to the outflow port.

7. The sheath cap assembly of Embodiment 6, wherein the pressure sensoris positioned in the outflow tubing.

8. The sheath cap assembly of any one of Embodiments 1 to 7, furthercomprising a light transmitter configured to transmit light across fluidflowing out of the sheath.

9. The sheath cap assembly of Embodiment 8, further comprising anoptical sensor configured to detect an amount of light absorbed by thefluid flowing out of the sheath.

10. The sheath cap assembly of Embodiment 8, wherein the processing unitis configured to direct fluid flow through the inflow port or theoutflow port based on the detect amount of light absorbed.

11. The sheath cap assembly of Embodiment 8, further comprising outflowtubing connected to the outflow port, the light transmitter positionedto transmit light across the outflow tubing.

12. The sheath cap assembly of any one of Embodiments 1 to 11, whereinthe processing unit is configured to determine a pressure at a distalend of the sheath based on the pressure measurement.

13. A sheath cap assembly configured to enclosed a proximal end of asheath, the cap comprising:

-   -   a main body portion comprising:        -   a wall portion shaped to surround the proximal end of the            sheath;        -   a closed proximal end portion; and        -   an open distal end portion;    -   an inflow port on the main body portion, the inflow port        providing access from an irrigation source to a lumen of the        sheath when the sheath cap is secured to the sheath;    -   an outflow port on the main body portion, the outflow port        providing an outlet for fluid flowing out of the sheath when the        sheath cap is secured to the sheath;    -   a light transmitter configured to transmit light across the        fluid flowing out of the sheath;    -   an optical sensor configured to detect an amount of light        absorbed by the fluid flowing out of the sheath; and    -   a processing unit configured to direct fluid through at least        one of the inflow port and the outflow port based on the        detected amount of absorbed light.

14. The sheath cap assembly of Embodiment 13, wherein the closedproximal end portion comprises an opening through which an endoscope canbe introduced.

15. The sheath cap assembly of Embodiment 14, wherein the openingcomprises a sealing structure configured to form a seal around theendoscope when the endoscope is introduced through the opening.

16. The sheath cap assembly of any one of Embodiments 13 to 15, furthercomprising a closure mechanism configured to secure the sheath cap tothe sheath.

17. The sheath cap assembly of any one of Embodiments 13 to 16, whereinthe optical sensor is positioned in the outflow port.

18. The sheath cap assembly of any one of Embodiments 13 to 17, furthercomprising outflow tubing connected to the outflow port.

19. The sheath cap assembly of Embodiment 18, wherein the optical sensoris connected to the outflow tubing.

20. A system for controlling pressure during percutaneous and endoscopicsurgery, the system comprising:

-   -   an endoscope having a proximal portion and a distal portion, the        endoscope comprising:        -   an inflow port providing access to an inflow channel            extending from the inflow port to the distal portion of the            endoscope; and        -   an outflow port providing access to an outflow channel            extending from the outflow port to the distal portion of the            endoscope;    -   a pressure sensor connected to the endoscope, the pressure        sensor configured to generate a pressure measurement; and    -   a processing unit configured to direct fluid through at least        one of the inflow port and the outflow port based on the        pressure measurement.

21. The system of Embodiment 20, wherein the pressure sensor is in theoutflow port of the endoscope.

22. The system of Embodiment 20, wherein the pressure sensor ispositioned in a distal section of the endoscope

23. The system of any one of Claims 20 to 21, wherein the endoscopecomprises an input control configured to receive a desired pressurevalue.

24. The system of Embodiment 23, wherein the processing unit isconfigured to increase flow of an irrigant through the inflow port whenthe pressure measurement is less than the desired pressure value.

25. The system of Embodiment 23 or 24, wherein the processing unit isconfigured to increase flow of a fluid out of the outflow port when thepressure measurement is greater than the desired pressure value.

26. The system of any one of Embodiments 20 to 25, wherein the endoscopefurther comprises a light emitter that transmits light across an outflowof fluid and the optical sensor detects an amount of light absorbed bythe outflow of fluid.

27. The system of Embodiment 26, wherein the processing unit isconfigured to direct fluid inflow or outflow based on the amount ofdetected light.

28. A system for controlling pressure during percutaneous and endoscopicsurgery, the system comprising:

-   -   a sheath having a proximal portion and a distal portion, the        sheath comprising:        -   an inflow port providing access to an inflow channel            extending from the inflow port to the distal portion of the            sheath; and        -   an outflow port providing access to an outflow channel            extending from the outflow port to the distal portion of the            sheath;    -   a pressure sensor connected to the sheath, the pressure sensor        configured to generate a pressure measurement; and    -   a processing unit configured to control fluid through at least        one of the inflow port and the outflow port based on the        pressure measurement.

29. The system of Embodiment 28, wherein the pressure sensor ispositioned in the outflow port of the sheath.

30. The system of Embodiment 28, wherein the pressure sensor ispositioned at a distal section of the sheath

31. The system of any one of Embodiments 28 to 30, wherein the sheathcomprises an input control configured to receive a desired pressurevalue.

32. The system of Embodiment 31 wherein the processing unit isconfigured to increase flow of an irrigant through the inflow port whenthe pressure measurement is less than the desired pressure value.

33. The system of Embodiment 31 or 32, wherein the processing unit isconfigured to increase flow of a fluid out of the outflow port when thepressure measurement is greater than the desired pressure value.

34. The system of any one of Embodiments 28 to 33, further comprising acap configured to close a proximal end of the sheath.

35. The system of Embodiment 34, wherein the cap is configured toreceive an endoscope.

36. The system of any one of Embodiments 28 to 35, wherein the sheathfurther comprises a light emitter that transmits light across an outflowof fluid from the sheath and an optical sensor detects an amount oflight absorbed by the outflow of fluid.

37. The system of Embodiment 36, wherein the processing unit isconfigured to adjust fluid inflow or outflow if the detected absorbedlight is greater than a prescribed level of light.

38. The system of any one of Embodiments 28 to 37, further comprising anendoscope configured to be introduced through the sheath, the endoscopehaving a proximal portion and a distal portion, the endoscopecomprising:

-   -   an endoscopic inflow port providing access to an inflow channel        extending from the inflow port to the distal portion of the        endoscope;    -   an endoscopic outflow port providing access to an outflow        channel extending from the outflow port to the distal portion of        the endoscope;    -   an endoscopic pressure sensor positioned on the endoscope, the        endoscopic pressure sensor configured to generate a second        pressure measurement; and    -   an endoscopic processing unit configured to control fluid        through at least one of the endoscopic inflow port and the        endoscopic outflow port based on the second pressure        measurement.

39. A method of controlling pressure in a renal collecting system, themethod comprising:

-   -   positioning a distal end of an endoscope in the collecting        system, the endoscope comprising:        -   an inflow port providing access to an inflow channel            extending from the inflow port to a distal portion of the            endoscope;        -   an outflow port providing access to an outflow channel            extending from the outflow port to the distal portion of the            endoscope;        -   a pressure sensor positioned on the endoscope, the pressure            sensor configured to generate a pressure measurement; and        -   a processing unit configured to control fluid through at            least one of the inflow port and the outflow port based on            the pressure measurement;    -   measuring the pressure in the collecting system; and    -   directing fluid flow through at least one of the inflow port and        the outflow port based on the pressure measurement.

40. The method of Embodiment 39, further comprising inputting a desiredpressure value into an input control of the endoscope.

41. The method of Embodiment 40, further comprising increasing flow ofan irrigant through the inflow port when the pressure measurement isless than the desired pressure value.

42. The method of Embodiment 39 or 40, further comprising increasingflow of a fluid out of the outflow port when the pressure measurement isgreater than the desired pressure value.

43. The method of any one of Embodiments 39 to 42, further comprisingtransmitting light through an outflow of fluid and detecting an amountof light absorbed by the outflow of fluid.

44. The method of Embodiment 43, further comprising directing fluidinflow through at least one of the inflow port and the outflow port ifthe amount of absorbed light is greater than a prescribed level oflight.

45. A method of controlling pressure in a renal collecting system, themethod comprising:

-   -   positioning a distal end of a sheath in the collecting system,        the endoscope comprising:        -   an inflow port providing access to an inflow channel            extending from the inflow port to a distal portion of the            sheath;        -   an outflow port providing access to an outflow channel            extending from the outflow port to the distal portion of the            sheath;        -   a pressure sensor positioned on the sheath, the pressure            sensor configured to generate a pressure measurement; and        -   a processing unit configured to control fluid through at            least one of the inflow port and the outflow port based on            the pressure measurement;    -   measuring the pressure in the collecting system; and    -   directing fluid flow through at least one of the inflow port and        the outflow port based on the pressure measurement.

46. The method of Embodiment 45, further comprising inputting a desiredpressure value into an input control of the endoscope.

47. The method of Embodiment 46, further comprising increasing flow ofan irrigant through the inflow port when the pressure measurement isless than the desired pressure value.

48. The method of Embodiment 45 or 46, further comprising increasingflow of a fluid out of the outflow port when the pressure measurement isgreater than the desired pressure value.

49. The method of any one of Embodiments 45 to 48, further comprisingtransmitting light across an outflow of fluid and detecting an amount oflight absorbed by the outflow of fluid.

50. The method of Embodiment 49, further comprising directing fluidinflow through at least one of the inflow port and the outflow port ifthe amount of absorbed light is greater than a prescribed level oflight.

1. A sheath cap assembly configured to enclosed a proximal end of asheath, the cap comprising: a main body portion comprising: a wallportion shaped to surround the proximal end of the sheath; a closedproximal end portion; and an open distal end portion; an inflow port onthe main body portion, the inflow port providing access from anirrigation source to a lumen of the sheath when the sheath cap issecured to the sheath; an outflow port on the main body portion, theoutflow port providing an outlet for fluid flowing out of the sheathwhen the sheath cap is secured to the sheath; a pressure sensorconnected to the sheath cap, the pressure sensor configured to generatea pressure measurement; and a processing unit configured to direct fluidthrough at least one of the inflow port and the outflow port based onthe pressure measurement.
 2. The sheath cap assembly of claim 1, whereinthe closed proximal end portion comprises an opening through which anendoscope can be introduced.
 3. The sheath cap assembly of claim 2,wherein the opening comprises a sealing structure configured to form aseal around the endoscope when the endoscope is introduced through theopening.
 4. The sheath cap assembly of claim 1, further comprising aclosure mechanism configured to secure the sheath cap to the sheath. 5.The sheath cap assembly of claim 1, wherein the pressure sensor ispositioned in the outflow port.
 6. The sheath cap assembly of claim 1,further comprising outflow tubing connected to the outflow port.
 7. Thesheath cap assembly of claim 6, wherein the pressure sensor ispositioned in the outflow tubing.
 8. The sheath cap assembly of claim 1,further comprising a light transmitter configured to transmit lightacross fluid flowing out of the sheath.
 9. The sheath cap assembly ofclaim 8, further comprising an optical sensor configured to detect anamount of light absorbed by the fluid flowing out of the sheath.
 10. Thesheath cap assembly of claim 8, wherein the processing unit isconfigured to direct fluid flow through the inflow port or the outflowport based on the detect amount of light absorbed.
 11. The sheath capassembly of claim 8, further comprising outflow tubing connected to theoutflow port, the light transmitter positioned to transmit light acrossthe outflow tubing.
 12. The sheath cap assembly of claim 1, wherein theprocessing unit is configured to determine a pressure at a distal end ofthe sheath based on the pressure measurement.
 13. A sheath cap assemblyconfigured to enclosed a proximal end of a sheath, the cap comprising: amain body portion comprising: a wall portion shaped to surround theproximal end of the sheath; a closed proximal end portion; and an opendistal end portion; an inflow port on the main body portion, the inflowport providing access from an irrigation source to a lumen of the sheathwhen the sheath cap is secured to the sheath; an outflow port on themain body portion, the outflow port providing an outlet for fluidflowing out of the sheath when the sheath cap is secured to the sheath;a light transmitter configured to transmit light across the fluidflowing out of the sheath; an optical sensor configured to detect anamount of light absorbed by the fluid flowing out of the sheath; and aprocessing unit configured to direct fluid through at least one of theinflow port and the outflow port based on the detected amount ofabsorbed light.
 14. The sheath cap assembly of claim 13, wherein theclosed proximal end portion comprises an opening through which anendoscope can be introduced.
 15. The sheath cap assembly of claim 14,wherein the opening comprises a sealing structure configured to form aseal around the endoscope when the endoscope is introduced through theopening.
 16. The sheath cap assembly of claim 13, further comprising aclosure mechanism configured to secure the sheath cap to the sheath. 17.The sheath cap assembly of claim 13, wherein the optical sensor ispositioned in the outflow port.
 18. The sheath cap assembly of claim 13,further comprising outflow tubing connected to the outflow port.
 19. Thesheath cap assembly of claim 18, wherein the optical sensor is connectedto the outflow tubing.